The Morphology Core will have four responsibilities in the program project: (1) provide the leaders and investigators of the five projects with expert advice in the selection of optimal morphological techniques to address specific questions and problems in their research, (2) perform advanced morphological applications that will include in situ hybridization, confocal laser scanning microscopy, plastic 1 micrometer section light microscopy, transmission electron microscopy, and electron microscopic immunocytochemistry, (3) provide expertise in interpreting results obtained with morphological techniques, (4) allocate the equipment, personnel, and other resources of the core fairly and to the optimal performance of the program project's research objectives. Dr. Ann Dvorak will have ultimate responsibility for administering the core but she will be assisted in this by Lawrence F. Brown, M.D. and Eliza Vasile, Ph.D. Dr. A. Dvorak has considerable expertise in light and electron microscopy and in electron microscopic immunocytochemistry. Dr. Brown has expertise in in situ hybridization and Dr. Vasile in confocal laser scanning microscopy. Each of the three core directors will have day-to-day responsibility for managing the equipment and personnel in her or his area of expertise.